It has been estimated that there are over 20 thousand ant species (Hölldobler and Wilson, The Ants. Harvard University Press, Cambridge, 1990; Smith et al., Cold Spring Harb. Protoc. 4:1, 2009), over 12,500 currently described (antbase.org, 15 Jan. 2010) some of which play a large role in destroying (Lessard et al., Ecology 90:2664, 2009; Porter and Savignano, Ecology 71:2095, 1990) or maintaining the structure of ecological communities (Hölldobler and Wilson, 1990). The Myrmicinae subfamily is the largest of the 21 extant subfamilies in the ants (Hymenoptera: Formicidae) (Bolton, Mem. Am. Entomol. Inst. 71:1, 2003). The Myrmicinae subfamily includes about 140 genera within the group, including species with a functional sting (such as ants in the genus Solenopsis, one of which is S. invicta, known as the “red imported fire ant,” and Myrmica rubra, also known as the European fire ant or common red ant, a species of ant of the genus Myrmica), and fungus-growing ants (of the tribe Attini) that include leafcutter ants (genus Atta and genus Acromyrmex). These ants are considered pests in commercial, agricultural, and residential settings, causing significant damage and injury to plants and animals alike. For example, M. pharaonis is described as “a pest in heated buildings, bakeries, etc. in many non-tropical countries . . . they carry pathogenic bacteria, have the capacity to transmit disease and are able to enter even highly sophisticated isolation units.” See Beatson, Lancet 2: 435 (1872).
Ants use a complex chemosensory system involving a mixture of semiochemicals for within and between species interactions (i.e., recruitment, nestmate recognition, alarm, territorial marking, competition, etc.) (Attygalle and Morgan, Chem. Soc. Rev. 13:245, 1984; Hölldobler and Carlin, J Comp Physiol A. 161:567, 1987). Many of the glandular substances are small volatile molecules and although many still need to be studied to determine their function, a large number have been identified (Attygalle and Morgan, 1984).